Electric heater.



EL KUHN.

ELECTRIC HEATER.

APYLIUATNN NLED MAR. 2z, 1909,

929,095,v Patented July 27,1909.

Uni-"ren sTAe-ES PATENT oFiuoE.

Fl'tlbl KUHN.. F DETROIT, ltlICIlIGN,y ASSIGNOR TO. AMERICN ELECTRICAL HEATER (.llPANXV'NOF DETROll, MICHIGAN, A CORPORATION OI" MICHIGAN.

ELECTRIC HEATER.'

To all "whom t may concern:

'i rBeit known that L'Fninvk .Kluun a citi zen of the United 'States'o'f America, residin" at Detroit, in the county of lfl'layne and tate of Michigan, have invented certain new yand useful Improvements in Electric Heaters, of-,Whieh the following' is a specification, reference being had therein to illustrating the electrical` terminal connec` -tions; Fig. 3 is a .section illustrating the clamped by screws C to a dovvnvvardly-prothe accompanying drawings.

- It is the object of theinvention to provide a construction ,nf electrical heater particun larly adapted for use as a hot plate, and the constructionconsists in certain features of construction asl hereinafter set forth.

In the drawings-Figure Iris a perspec tive View of the heater; Fig. 2 is a vertical 'section vthrough a portion of the heater,

jecting bossor thickened ortion D of the plate. nected to flexible terminals E preferably formed of resilient sheet metal, and having secured thereto at their outer ends the coupling pins F. A

To diminish the heat lost from the under side of the plate and the unit, thelatter is preferably inclosed in a casing G forming an air chamber. This casing 1s preferably formed of' sheet metal, being provided with an annular upwardly-extending flange H, engaging with 'a marginal bearing upon a `hot plate, so as to forma substantially air tight joint, as Well as'aflording support-,tor

the plate. .flange for the passage outward of the coupling pins F, and these are positioned There 'are also apertures in this and insulated from the casing by insulator a suitable' base, and this, as shown, is formedk by a base ring .l struck up out of the sheet bushings I sleeved thereon projecting through the apertures in `the easing andV bearingagainst the inner side ofthe latter. The casing Gr is preferablysupported by metal. The vcasing G is provided with downwardly-extending lugs L, which, as

Specification of Letters Patent. appueauoamed `innen 22, i909. semina. essere?, l

The end sections o the unit are congarentgauiy'z?, 190e.

shovvu,v are struck 'outiroz the metal forni ing the bot-torn` of the Casin G, and are.' riveted to the ring J'. Additional sup orts are formed by handle sections M Whit: i, as illustrated in Fig. 3,.have shanksN extending into thevspace between vthe ring J and ,casingGn These,shanks are `pvrelerably se -cured by riveting, both to the under side of the Casin G and to the top of the ring, thus forming a lirni connection.

With the construction as described in operation the heat generated in the unit is .distributed by conduction directly to the plate. Moreover, both the unit and the plate are free from contact with other parts of the structure, with exception of the annular flange H, which is at the periphery of the plate. As this llangeis formed ofthln metal,

the, heat conducting section is relatively small. Waste of heat'is further prevented by the air space Within the' easing Gr, and by forming the surface of the casing .of bright nletal-such as nichel-:which isa poor radiator. Conduction of the heat to the base ring is limited by the small section of the supports formed by the 4lugs L and handle Shanks N, so that` this base ring remains Acomparatively cool. The legs K may, if

desired, be'provided with tips O of rubber or other poorconductin substance, thus permitting the heater to lar e table Without doing injury.l

l hat I claim as my invention is: v1.44511 eleetricallieater .comprisin a hot plate, having va'heating` unit secure to the under side thereof, and a casing sur ounding placedppou a said unit and spaced therefrom, having a u marginal supporting bearin forsaid late and forming an air charnbr on the llindei side thereof.-

2. An electrical heater comprising aV hot plate, 'a heating unit secured to the underv side thereof, andl a, casing formed -of-sheet .t

metal havin an. annular flange forming' a suppertinstring for the .inargi of the plate, an formingan air chamber: beneath said plate and'unit. f n

3. An electrical unit comprising a. het

plate, a Aheating unit' securedto'itheimler side of said plate, 'a casing having a Vniar` ginal supporting bearing for said plate and forming an air chamber beneath said plate and unit, a terminal connection secured to said unit projecting' v'outvmrd through an aperture in said casing, and an ,insulator side hero, n, Shea-, 'mami musing having zu l pfphexal Hangs forming; al mnygnal support 'fof Said' pla/te! and haw mim Salif, casing', :md Suppofs 0f sommeil therewit', ay base ring Space- :'l'om Casing, and n support for said Lasng upon said buse ying struck. out from iba meisoff the bottmn nii the casing.

'3. All electrical hemmt comprising a plate, a heating unit :secured to the under side thereof, 2L casing Surmmdng Said Unk, a

"ms/e, ring' Spa-sed fram said Casing'. and a.

)l hfmde having :L shank projecting into 'bha Spams 'between Said Casing and fing, und, 5:55 ml'ied to each.

g'n tesfun y Where' a): my signa "zum in presence tw@ Witnesses.

FRANK KUHN. 

